Diagnosis and treatment of focal splenic lesions.

The spleen can be affected by many conditions, some of which are easily diagnosed by conventional imaging, mainly using computed tomography scans and magnetic resonance imaging. Despite the contribution of functional radiology techniques such as positron emission tomography, it is sometimes difficult to diagnose certain focal splenic lesions and definitive diagnosis sometimes requires histological confirmation by percutaneous biopsy or more rarely by diagnostic intervention. Once a diagnosis has been established, treatment is based mainly on surgery: total splenectomy for malignant lesions, or partial splenectomy whenever possible for benign lesions benign that are symptomatic and/or at risk of rupture.

Interobserver agreement issues in radiology.

Agreement between observers (i.e., inter-rater agreement) can be quantified with various criteria but their appropriate selections are critical. When the measure is qualitative (nominal or ordinal), the proportion of agreement or the kappa coefficient should be used to evaluate inter-rater consistency (i.e., inter-rater reliability). The kappa coefficient is more meaningful that the raw percentage of agreement, because the latter does not account for agreements due to chance alone. When the measures are quantitative, the intraclass correlation coefficient (ICC) should be used to assess agreement but this should be done with care because there are different ICCs so that it is important to describe the model and type of ICC being used. The Bland-Altman method can be used to assess consistency and conformity but its use should be restricted to comparison of two raters.

Computed tomography features of acinar cell carcinoma of the pancreas.

PURPOSE: To report the computed tomography (CT) features of pancreatic acinar cell carcinoma (ACC) and identify CT features that may help discriminate between pancreatic ACC and pancreatic ductal adenocarcinoma (PDA). MATERIALS AND METHODS: The CT examinations of 20 patients (13 men, 7 women; mean age, 66.5±10.7 [SD] years; range: 51-88 years) with 20 histopathologically proven pancreatic ACC were reviewed. CT images were analyzed qualitatively and quantitatively and compared to those obtained in 20 patients with PDA. Comparisons were performed using univariate analysis with a conditional logistic regression model. RESULTS: Pancreatic ACC presented as an enhancing (20/20; 100%), oval (15/20; 75%), well-delineated (14/20; 70%) and purely solid (13/20; 65%) pancreatic mass with a mean diameter of 52.6±28.0 (SD) mm (range: 24-120mm) in association with visible lymph nodes (14/20; 70%). At univariate analysis, well-defined margins (Odds ratio [OR], 7.00; P=0.005), nondilated bile ducts (OR, 9.00; P=0.007), visible lymph nodes (OR, 4.33; P=0.028) and adjacent organ involvement (OR, 5.67; P=0.02) were the most discriminating CT features to differentiate pancreatic ACC from PDA. When present, lymph nodes were larger in patients with pancreatic ACC (14±4.8 [SD]; range: 7-25mm) than in those with PDA (8.8±4.1 [SD]; range: 5-15mm) (P=0.039). CONCLUSION: On CT, pancreatic ACC presents as an enhancing, predominantly oval and purely solid pancreatic mass that most frequently present with no bile duct dilatation, no visible lymph nodes, no adjacent organ involvement and larger visible lymph nodes compared to PDA.

Prediction of tumor grade and lymphovascular space invasion in endometrial adenocarcinoma with MR imaging-based radiomic analysis.

PURPOSE: To evaluate the capabilities of two-dimensional magnetic resonance imaging (MRI)-based texture analysis features, tumor volume, tumor short axis and apparent diffusion coefficient (ADC) in predicting histopathological high-grade and lymphovascular space invasion (LVSI) in endometrial adenocarcinoma. MATERIALS AND METHODS: Seventy-three women (mean age: 66±11.5 [SD] years; range: 45-88 years) with endometrial adenocarcinoma who underwent MRI of the pelvis at 1.5-T before hysterectomy were retrospectively included. Texture analysis was performed using TexRAD® software on T2-weighted images and ADC maps. Primary outcomes were high-grade and LVSI prediction using histopathological analysis as standard of reference. After data reduction using ascending hierarchical classification analysis, a predictive model was obtained by stepwise multivariate logistic regression and performances were assessed using cross-validated receiver operator curve (ROC). RESULTS: A total of 72 texture features per tumor were computed. Texture model yielded 52% sensitivity and 75% specificity for the diagnosis of high-grade tumor (areas under ROC curve [AUC]=0.64) and 71% sensitivity and 59% specificity for the diagnosis of LVSI (AUC=0.59). Volumes and tumor short axis were greater for high-grade tumors (P=0.0002 and P=0.004, respectively) and for patients with LVSI (P=0.004 and P=0.0279, respectively). No differences in ADC values were found between high-grade and low-grade tumors and for LVSI. A tumor short axis≥20mm yielded 95% sensitivity and 75% specificity for the diagnosis of high-grade tumor (AUC=0.86). CONCLUSION: MRI-based texture analysis is of limited value to predict high grade and LVSI of endometrial adenocarcinoma. A tumor short axis≥20mm is the best predictor of high grade and LVSI.

Standardization of dermoscopic terminology and basic dermoscopic parameters to evaluate in general dermatology (non-neoplastic dermatoses): an expert consensus on behalf of the International Dermoscopy Society.

BACKGROUND: Over the last few years, several articles on dermoscopy of non-neoplastic dermatoses have been published, yet there is poor consistency in the terminology among different studies. OBJECTIVES: We aimed to standardize the dermoscopic terminology and identify basic parameters to evaluate in non-neoplastic dermatoses through an expert consensus. METHODS: The modified Delphi method was followed, with two phases: (i) identification of a list of possible items based on a systematic literature review and (ii) selection of parameters by a panel of experts through a three-step iterative procedure (blinded e-mail interaction in rounds 1 and 3 and a face-to-face meeting in round 2). Initial panellists were recruited via e-mail from all over the world based on their expertise on dermoscopy of non-neoplastic dermatoses. RESULTS: Twenty-four international experts took part in all rounds of the consensus and 13 further international participants were also involved in round 2. Five standardized basic parameters were identified: (i) vessels (including morphology and distribution); (ii) scales (including colour and distribution); (iii) follicular findings; (iv) 'other structures' (including colour and morphology); and (v) 'specific clues'. For each of them, possible variables were selected, with a total of 31 different subitems reaching agreement at the end of the consensus (all of the 29 proposed initially plus two more added in the course of the consensus procedure). CONCLUSIONS: This expert consensus provides a set of standardized basic dermoscopic parameters to follow when evaluating inflammatory, infiltrative and infectious dermatoses. This tool, if adopted by clinicians and researchers in this field, is likely to enhance the reproducibility and comparability of existing and future research findings and uniformly expand the universal knowledge on dermoscopy in general dermatology. What's already known about this topic? Over the last few years, several papers have been published attempting to describe the dermoscopic features of non-neoplastic dermatoses, yet there is poor consistency in the terminology among different studies. What does this study add? The present expert consensus provides a set of standardized basic dermoscopic parameters to follow when evaluating inflammatory, infiltrative and infectious dermatoses. This consensus should enhance the reproducibility and comparability of existing and future research findings and uniformly expand the universal knowledge on dermoscopy in general dermatology.

A proposal for standardized magnetic resonance imaging (MRI) descriptors of abnormally invasive placenta (AIP) - From the International Society for AIP.

Abnormally invasive placenta (AIP) is used to describe a placenta that does not separate naturally after delivery and cannot be extirpated without causing abnormally high blood loss. Recently, the use of a standardized terminology for descriptors of AIP signs seen on ultrasound has been prosed but to date no such unified descriptors have been developed for magnetic resonance imaging (MRI). The purpose of this paper is to propose a unified terminology based on a consensus opinion from the members of the International Society for AIP (IS-AIP) that include obstetricians, gynecologists, radiologists, pathologists, anesthesiologists and basic science researchers. We assume that using these standardized MRI descriptors for AIP will be useful for clinical use, education, teaching and future research projects, thus assumably improving care of patients with this condition. In addition, using a uniform terminology for AIP should become the first step of a standardized MRI report.

MR imaging features of pancreatic acinar cell carcinoma.

PURPOSE: This study aimed to report the magnetic resonance imaging (MRI) features of acinar cell carcinoma (ACC) of the pancreas including diffusion-weighted MRI findings. MATERIALS AND METHODS: The MRI examinations of five patients (3 men, 2 women; median age, 61years) with histopathologically proven ACC of the pancreas were retrospectively reviewed. MR images were analyzed qualitatively (location, shape, homogeneity, signal intensity, vascular involvement and extrapancreatic extent of ACC) and quantitatively (tumor size, apparent diffusion coefficient [ADC] and normalized ADC of ACC). RESULTS: All ACC were visible on MRI, presenting as an oval pancreatic mass (5/5; 100%), with moderate and heterogeneous enhancement (5/5; 100%), with a median transverse diameter of 43mm (Q1, 35; Q3, 82mm; range: 30-91mm). Tumor capsule was visible in 4/5 ACC (80%) and Wirsung duct enlargement in 2/5 ACC (40%). On diffusion-weighted MRI, all ACC (5/5; 100%) were hyperintense on the 3 b value images. Median ADC value of ACC was 1.061×10-3mm2/s (Q1, 0.870×10-3mm2/s; Q3, 1.138×10-3mm2/s; range: 0.834-1.195×10-3mm2/s). Median normalized ADC ratio of ACC was 1.127 (Q1, 1.071; Q3, 1.237; range: 1.054-1.244). CONCLUSIONS: On MRI, ACC of the pancreas presents as a large, oval pancreatic mass with moderate and heterogeneous enhancement after intravenous administration of a gadolinium chelate, with restricted diffusion and a median ADC value of 1.061×10-3mm2/s on diffusion-weighted MRI. Further studies however are needed to confirm our findings obtained in a limited number of patients.

Preoperative evaluation of small bowel complications in Crohn's disease: comparison of diffusion-weighted and contrast-enhanced MR imaging.

PURPOSE: To compare the accuracy of MR enterography (MRE) using combined T2-weighted and contrast-enhanced (CE) sequences with that of combined T2- and diffusion-weighted (DW) sequences for the detection of complex enteric Crohn's disease (CD). MATERIALS: Thirty-eight patients who underwent surgery for CD complications and preoperative MRE from 2011 to 2016 were included. MRE examinations were blindly analyzed independently by one junior and one senior abdominal radiologist for the presence of fistula, stenosis and abscesses. During a first reading session, T2-weighted images (WI), steady-state sequences and DW-MRE were reviewed (set 1). During a separate distant session, T2-WI, True-FISP and CE-MRE were reviewed (set 2). Performance of each reader was evaluated by comparison with the standard of reference established using intraoperative and pathological findings. RESULTS: Forty-eight fistulas, 43 stenoses and 11 abscesses were found. For the senior radiologist, sensitivity for the detection of fistula, stenosis and abscess ranged from 80% to 100% for set 1 and 88% to 100% for set 2 and specificity ranged from 56% to 70% for set 1 and 53% to 93% for set 2, with no significant difference between the sets (p = 0.342-0.429). For the junior radiologist, sensitivity ranged from 53% to 63% for set 1 and 64% to 88% for set 2 and specificity ranged from 0% to 25% for set 1 and 17% to 40% for set 2 (p = 0.001 and 0.007, respectively). CONCLUSION: For a senior radiologist, DW-MRE has similar sensitivity as CE-MRE for the detection of CD complications. For a junior radiologist, CE-MRE yields the best results compared with DW-MRE. KEY POINTS: • For experienced readers, DWI has similar diagnostic capability as contrast-enhanced MR imaging for the diagnosis of Crohn's disease complications. • For senior radiologists, gadolinium chelate injection could be waived for the diagnosis of Crohn's disease complications. • The interpretation of DWI for Crohn's disease complications requires some experience.

Volvulus of the sigmoid colon is associated with hypotrophy of the left lateral segment of the liver and the absence of sigmoid diverticulum.

PURPOSE: To investigate the possible relationships between sigmoid diverticula, the volume of the left lateral segment of the liver and sigmoid colon volvulus. MATERIAL AND METHODS: The presence of sigmoid diverticula was analyzed in 36 patients (24 men, 12 women; mean age, 70.77±19.86 [SD] years) with sigmoid volvulus (group 1). The volumes of left lateral segment of the liver (i.e., segments 2 and 3 and further referred to as liver 1), liver 2 (i.e., segments 1, 4, 5, 6, 7 and 8), total liver volume and liver volume ratio (LVR) (i.e., [liver 1/liver 2]×100) were calculated from abdominal CT performed distantly from the acute episode of sigmoid volvulus. Results of volumetric measurements in group 1 were compared with those of two groups of age and gender-matched control patients without hepatopathy: one patient group with sigmoid diverticula (group 2) and one group without sigmoid diverticula (group 3). RESULTS: No patients with sigmoid volvulus had diverticulum. Liver 1 volume was lower in group 1 (193.8cm3) than in group 2 (273.75cm3) (P=0.0003). Mean LVR was greater in group 2 (24.18%) than in group 1 (14.46%) (P=1×10-7) and group 3 (18.36%) (P=0.003). Mean LVR was greater in group 3 than in group 1 (P=0.01). No significant differences in liver 2 volume and total liver volumes were found between the 3 groups. CONCLUSION: Elasticity of colon wall associated with relative hypotrophy of left lateral segment of the liver are significantly associated with sigmoid volvulus. Further studies are needed to elucidate the pathophysiological mechanisms behind this association.